I have a 2011 RAV4 limited with factory navigation. I want to install Sirus Xm because my vehicle is not equipped with it. However my radio does have the AM/SAT button so I would like to keep it stock? What does my vehicle need to get this function? Does anyone have the OEM nav with xm radio? I pretty much would like to know what my car is missing that I may need to install, I'm trying to keep it under $150 as I've seen Xm modulators that will plug into my radio and make that function work I wanted to see if I can keep it as OEM as possible with the Xm function. Thanks in advance.